For the sake of safety and convenience, it is desirable to know whether an electrical extension cord is being supplied with power. Heretofore, prior electrical connectors have used lamps of the neon variety to visually indicate that power is being supplied to the connector. U.S. Pat. No. 4,671,597 shows an electrical extension cord having a lamp which is provided at the female end of the cord for indicating the availability of power to the plug. The female end is formed from a multiple part assembly which includes an enclosure within which a lamp is connected. One side of the enclosure includes a transparent plastic window which permits the lamp to be seen from the outside of the connector. The lamp is illuminated when power is supplied to the female end of the cord. U.S. Pat. No. 5,207,594 discloses an elongated extension cord with a lamp provided in both the male and female ends of the extension cord for indicating the availability of power to the plugs.
Such extension cord receptacles are disadvantageous in several respects. Firstly, the receptacles are molded from multiple part constructions. The multiple part construction of the receptacle assemblies can fail to provide adequate protection to the electrical connections therein from stresses due to mechanical shock.
Secondly, these light sources are usually embedded in the receptacle or connectors during the molding process. The light sources are not rigidly affixed to any of the parts of the receptacle (they are usually attached by wires) and as a result are only kept in place by the molded material such as a polyvinyl plastic. Thus, when extension cords with light sources molded in the receptacles, such as these, are used in an active work area where the cord is thrown about and handled roughly, the lamp can be vibrated and damaged. Further, parts of the light source may become loose and disconnected (such as the electrical connections), or may break. If a light source stops operating, the receptacle must be discarded as the light source cannot be replaced or repaired.